adds upx/git packages only if necessary

Jenkinsfile

@@ -75,6 +75,9 @@ podTemplate(
             container('golang') {
                 writeFile(file: workspace + "/test-chamber-13.lan.root.crt", text: functions.getLocalRootCA())
                 sh """
+                    if [ ! "/usr/bin/git" ] || [ ! -x "/usr/bin/git" ]; then
+                        apk add --no-cache git
+                    fi
                     apk add --no-cache curl gcc musl-dev
                     curl \
                       --silent \
@@ -117,7 +120,12 @@ sonar.go.coverage.reportPaths=cover.out
         stage("Build tplinkcmd") {
             container("golang") {
                 sh """
-                    apk add --no-cache upx
+                    if [ ! "/usr/bin/git" ] || [ ! -x "/usr/bin/git" ]; then
+                        apk add --no-cache git
+                    fi
+                    if [ ! "/usr/bin/upx" ] || [ ! -x "/usr/bin/upx" ]; then
+                        apk add --no-cache upx
+                    fi
                     go install -v ./...
                     GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -v -ldflags="-s -w" -tags timetzdata -o tplink ./cmd/tpstate
                     upx --lzma tplink